I bought the Fussy Brush serator and love it. I read the comments on their web page about the increase in performance and after I got it I tried a new set of brushes against a pair serated by the Fussy Brush serator on the same motor. The dyno showed alittle more power and rip from the Fussy Brushes. Not cheap but worth the money. Look them up at fussybrush.com.